This invention relates to a technique for mounting a semiconductor mechanical quantity measuring apparatus.
A technique for measuring the strain generated in an object of measurement has been developed using a strain gauge including a sensor having a thin tape member on which a metal foil photoetched in a grid is arranged. This strain gauge is bonded to the object of measurement so that the length of the metal foil is changed following the strain imposed on the object, and by measuring the changing resistance value of the metal foil, the strain of the object can be measured.
A strain gauge using a Cu—Ni alloy foil or Ni—Cr alloy foil is known as products that have so far been commercially available.
As a technique to secure and stabilize the attachment of the strain gauge, a strain gauge with a protector is disclosed in JP-A-09-053907. JP-A-07-35628, on the other hand, discloses a structure as technique to protect a strain gauge from an external environment by maintaining the moisture resistance and insulation.
In strain measurement, the strain generated in the object of measurement is required to be positively followed by the strain of a measurement unit. In the case where the strain is measured using a semiconductor mechanical quantity measuring apparatus, the rigidity of a thick silicon semiconductor substrate may make it difficult for the strain of the measurement unit to follow the strain of the object of measurement. In the case where the silicon semiconductor substrate is reduced in thickness, on the other hand, the effect of the wiring or the like members on the silicon surface may pose the problem of a disturbed strain of the measurement unit, resulting in a deteriorated measurement accuracy or the silicon being cracked in the process. In a protracted measurement operation or the measurement in a harsh environment, on the other hand, the breakage of the semiconductor, the separation of the object of measurement from the measurement unit and the operation failure due to moisture are problems to be obviated.